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| United States Patent |
5,086,122
|
|
Lawson
, et al.
|
February 4, 1992
|
Crosslinked chlorinated polyvinyl chloride resin compositions
Abstract
Chlorinated polyvinyl chloride resins when crosslinked have improved melt
strength in comparison with non-crosslinked chlorinated polyvinyl chloride
resins. Moreover, the crosslinked chlorinated polyvinyl chloride resins
have unexpected improved processing properties such as reduced processing
torgue in comparison with crosslinked polyvinyl chloride resins which upon
crosslinking exhibit increased processing torque. Various amounts of
non-crosslinked chlorinated polyvinyl chloride and/or non-crosslinked
polyvinyl chloride which does not affect said improved properties can be
blended with the cross-linked chlorinated polyvinyl chloride resins.
| Inventors:
|
Lawson; Dennis L. (Brunswick, OH);
Detterman; Robert E. (Elyria, OH)
|
| Assignee:
|
The B. F. Goodrich Company (Akron, OH)
|
| Appl. No.:
|
637394 |
| Filed:
|
January 4, 1991 |
| Current U.S. Class: |
525/235; 525/239; 525/329.5; 525/329.6; 525/331.2; 525/331.6 |
| Intern'l Class: |
C08F 008/22 |
| Field of Search: |
525/329.5,322.6,331.2,331.6,235,239
|
References Cited
U.S. Patent Documents
| 3100762 | Aug., 1963 | Shockney | 525/331.
|
| 3230203 | Jan., 1966 | Kuhne | 526/322.
|
| 3415797 | Dec., 1968 | Borsini et al. | 526/338.
|
| 3496253 | Feb., 1970 | Hamilton et al. | 525/306.
|
| 3535220 | Oct., 1970 | Kato et al. | 525/331.
|
| 3652733 | Mar., 1972 | Davonport | 525/306.
|
| 3736240 | May., 1973 | Weintraub | 525/331.
|
| 3763123 | Oct., 1973 | Waterman et al. | 526/338.
|
| 3808173 | Apr., 1974 | Orihashi | 525/331.
|
| 4006126 | Feb., 1977 | Rettore et al. | 525/331.
|
| 4031061 | Jun., 1977 | Thomas | 525/306.
|
| 4039732 | Aug., 1977 | Schoen et al. | 525/331.
|
| 4049517 | Sep., 1977 | Adachi et al. | 525/331.
|
Primary Examiner: Lipman; Bernard
Attorney, Agent or Firm: Powell; Joe A., Prout; William F., Dunlap; Thoburn T.
Parent Case Text
This is a division, of application Ser. No. 07/197,730, filed 05/23/88, now
U.S. Pat. No. 4,983,687.
Claims
What is claimed is:
1. A crosslinked chlorinated polyvinyl chloride resin composition,
comprising:
a crosslinked chlorinated polyvinyl chloride resin, said crosslinked
chlorinated polyvinyl chloride resin containing from about 58 percent to
about 70 percent by weight of chlorine therein, said crosslinked
chlorinated polyvinyl chloride resin made from a vinyl chloride monomer
and a crosslinking agent, said crosslinking agent containing two or more
polymerizable CH.sub.2 .dbd.C< groups per molecule, the composition
containing from about 0 percent to about 85 percent by weight of a
non-crosslinked chlorinated polyvinyl chloride resin based upon the total
weight of said non-crosslinked chlorinated polyvinyl chloride resin and
said crosslinked chlorinated polyvinyl resin, and containing from about 0
parts to about 40 parts by weight of a non-crosslinked polyvinyl chloride
resin per 100 parts by weight of said non-crosslinked chlorinated
polyvinyl chloride resin and said crosslinked chlorinated polyvinyl
chloride resin, the amount of said crosslinking agent being from about
0.025 parts to about 5.0 parts by weight for every 100 parts by weight of
said vinyl chloride monomer.
2. A crosslinked chlorinated polyvinyl chloride resin composition according
to claim 1, wherein the amount of said non-crosslinked chlorinated
polyvinyl chloride resin is from about 0 percent to about 50 percent by
weight based upon the total weight of said non-crosslinked chlorinated
polyvinyl chloride resin and said crosslinked chlorinated polyvinyl
chloride resin, and wherein the amount of said non-crosslinked polyvinyl
chloride is from about 0 parts to about 25 parts by weight per 100 parts
by weight of said non-crosslinked chlorinated polyvinyl chloride and said
crosslinked chlorinated polyvinyl chloride resin.
3. A crosslinked chlorinated polyvinyl chloride resin composition according
to claim 2, wherein said crosslinking agent is a
polyunsaturated-hydrocarbon, a polyunsaturated-polyester, a
polyunsaturated-polyether, a polyunsaturated-nitrile, a
polyunsaturated-acid anhydride, a polyunsaturated-ketone, a
polyunsaturated-alcohol, and combinations thereof.
4. A crosslinked chlorinated polyvinyl chloride resin composition according
to claim 3, wherein the amount of said crosslinking agent is from about
0.1 to about 2.0 parts by weight, and wherein said crosslinking agent is
divinyl benzene, diallyl phthalate, or combinations thereof.
5. A crosslinked chlorinated polyvinyl chloride resin composition according
to claim 4, wherein said composition contains said non-crosslinked
chlorinated polyvinyl chloride resin, wherein the amount of said
non-crosslinked chlorinated polyvinyl resin being from about 0 percent by
weight to about 25 percent by weight based upon the total weight of said
non-crosslinked chlorinated polyvinyl resin and said crosslinked
chlorinated polyvinyl resin, and wherein the amount of said chlorination
of said crosslinked chlorinated polyvinyl chloride resin is from about 65
percent to about 69 percent by weight.
6. A crosslinked chlorinated polyvinyl chloride resin composition according
to claim 1, wherein said crosslinked chlorinated polyvinyl chloride resin
is made from said vinyl chloride monomer and a vinyl component comonomer,
wherein the amount of said crosslinking agent is based upon 100 parts by
weight of said vinyl chloride monomer and said vinyl component comonomer,
said vinyl component comonomer being an ester of acrylic acid wherein said
ester portion contains from 1 to 12 carbon atoms, vinyl acetate, an ester
of methacrylic acid wherein said ester portion contains from 1 to 12
carbon atoms, styrene or a styrene derivative having a total of from 8 to
15 carbon atoms, vinyl naphthalene, a diolefin having a total of from 4 to
8 carbon atoms, a monoolefin having from 2 to 10 carbon atoms, and
combinations thereof, and wherein the amount of said vinyl component
comonomer is such to produce a copolymer containing from about 5 percent
to about 30 percent by weight of vinyl component repeating units therein.
7. A crosslinked chlorinated polyvinyl chloride resin composition according
to claim 2, wherein said crosslinked chlorinated polyvinyl chloride resin
is made from said vinyl chloride monomer and a vinyl component comonomer,
wherein the amount of said crosslinking agent is based upon 100 parts by
weight of said vinyl chloride monomer and said vinyl component comonomer,
said vinyl component comonomer being an ester of acrylic acid wherein said
ester portion contains from 1 to 12 carbon atoms, styrene or a styrene
derivative having a total of from 8 to 15 carbon atoms, vinyl naphthalene,
a diolefin having a total of from 4 to 8 carbon atoms, a monoolefin having
from 2 to 10 carbon atoms, and combinations thereof, and wherein the
amount of said vinyl component comonomer is such to produce a copolymer
containing from about 5 percent to about 30 percent by weight of vinyl
component repeating units therein.
8. A crosslinked chlorinated polyvinyl chloride resin composition according
to claim 3, wherein said crosslinked chlorinated polyvinyl chloride resin
is made from said vinyl chloride monomer and a vinyl acetate comonomer,
wherein the amount of said crosslinking agent is based upon 100 parts by
weight of said vinyl chloride monomer and said vinyl acetate comonomer,
wherein the amount of said vinyl acetate comonomer is such to produce said
copolymer having from about 7 percent to about 20 percent by weight of
vinyl acetate repeating units therein.
9. A crosslinked chlorinated polyvinyl chloride resin composition according
to claim 4, wherein said crosslinked chlorinated polyvinyl chloride resin
is made from said vinyl chloride monomer and a vinyl acetate comonomer,
wherein the amount of said crosslinking agent is based upon 100 parts by
weight of said vinyl chloride monomer and said vinyl acetate comonomer,
wherein the amount of said vinyl acetate is such to produce said copolymer
having from about 7 percent to about 20 percent by weight of vinyl acetate
repeating units therein.
10. A crosslinked chlorinated polyvinyl chloride resin composition
according to claim 5, wherein said crosslinked chlorinated polyvinyl
chloride resin is made from said vinyl chloride monomers and a vinyl
acetate comonomer, wherein the amount of said crosslinking agent is based
upon 100 parts by weight of said vinyl chloride monomer and said vinyl
acetate comonomer, wherein the amount of said vinyl acetate is such to
produce said copolymer having from about 7 percent to about 20 percent by
weight of vinyl acetate repeating units therein.
11. A crosslinked chlorinated polyvinyl chloride resin composition,
comprising:
a chlorinated polyvinyl chloride resin containing from about 58 percent to
about 70 percent by weight of chlorine therein, said chlorinated polyvinyl
chloride resin crosslinked with an effective amount of a crosslinking
agent so that the composition has reduced processing torque, said
crosslinking agent containing two or more polymerizable CH.sub.2 .dbd.C<
groups per molecule.
12. A crosslinked chlorinated polyvinyl chloride resin composition
according to claim 11, including from about 0 percent to about 85 percent
by weight of a non-crosslinked chlorinated polyvinyl chloride resin based
upon the total weight of said crosslinked chlorinated polyvinyl chloride
resin and said non-crosslinked chlorinated polyvinyl chloride resin, and
including from about 0 parts to about 45 parts by weight of a
non-crosslinked polyvinyl chloride resin per 100 parts by weight of said
crosslinked chlorinated polyvinyl chloride resin and said non-crosslinked
chlorinated polyvinyl chloride resin, and wherein said reduced processing
torque of said composition is at least 5 percent.
13. A crosslinked chlorinated polyvinyl chloride resin composition
according to claim 12, wherein said crosslinked chlorinated polyvinyl
chloride resin is made from a vinyl chloride monomer and a vinyl component
comonomer, said vinyl component comonomer being an ester of acrylic acid
wherein said ester portion contains from 1 to 12 carbon atoms, vinyl
acetate, an ester of methacrylic acid wherein said ester portion contains
from 1 to 12 carbon atoms, styrene or a styrene derivative having a total
of from 8 to 15 carbon atoms, vinyl naphthalene, a diolefin having a total
of from 4 to 8 carbon atoms, a monoolefin having from 2 to 10 carbon
atoms, and combinations thereof, and wherein the amount of said vinyl
component comonomer is such to produce a copolymer containing from about 5
percent to about 30 percent by weight of vinyl component repeating units
therein.
14. A crosslinked chlorinated polyvinyl chloride resin composition
according to claim 12, wherein said non-crosslinked chlorinated polyvinyl
chloride resin is from about 0 percent to about 50 percent by weight based
upon the total weight of said non-crosslinked chlorinated polyvinyl
chloride resin and said crosslinked chlorinated polyvinyl chloride resin,
and wherein the amount of said non-crosslinked polyvinyl chloride is from
about 0 parts to about 25 parts by weight per 100 parts by weight of said
non-crosslinked chlorinated polyvinyl chloride and said crosslinked
chlorinated polyvinyl chloride resin, and wherein said reduced processing
torque of said composition is at least 10 percent.
15. A crosslinked chlorinated polyvinyl chloride resin composition
according to claim 14, wherein said crosslinking agent is a
polyunsaturated-hydrocarbon, a polyunsaturated-polyester, a
polyunsaturated-polyether, a polyunsaturated-nitrile, a
polyunsaturated-acid anhydride, a polyunsaturated-ketone, a
polyunsaturated-alcohol, and combinations thereof, wherein said
composition contains said crosslinked chlorinated polyvinyl chloride resin
and said non-crosslinked chlorinated polyvinyl chloride resin, and wherein
the amount of said non-crosslinked chlorinated polyvinyl chloride resin is
from about 0 percent to about 25 percent by weight based upon the total
weight of said crosslinked chlorinated polyvinyl chloride resin and said
non-crosslinked chlorinated polyvinyl chloride resin, wherein said
crosslinked chlorinated polyvinyl chloride resin is made from a vinyl
chloride monomer, and wherein the amount of said effective amount of said
crosslinking agent is from about 0.25 to about 5.0 parts by weight for
every 100 parts by weight of said vinyl chloride monomer.
16. A crosslinked chlorinated polyvinyl chloride resin composition
according to claim 15, wherein said crosslinking agent is diallyl
phthalate, divinyl benzene, or combinations thereof, wherein the amount of
said crosslinking agent is from about 0.1 to about 2.0 parts by weight,
and wherein the amount of chlorination of said crosslinked chlorinated
polyvinyl chloride resin contains from about 65 percent to about 69
percent by weight of chlorine therein.
Description
FIELD OF THE INVENTION
The present invention relates to compositions containing crosslinked
chlorinated polyvinyl chloride (CPVC) resins which have unexpectedly been
found to have lower melt temperatures than non-crosslinked CPVC resins and
hence have favorable properties such as reduced processing torque, and the
like. Blends of such resins with non-detrimental amounts of
non-crosslinked CPVC (i.e. adverse affect on the processing properties)
can also be utilized.
BACKGROUND
Heretofore, CPVC resins have been produced and utilized in applications
wherein good chemical resistance, good flame retardancy, and good high
heat distortion properties were desirable. However, CPVC is generally
difficult to process and requires streamlined equipment. That is, the
equipment generally could not have any dead or lull spots therein inasmuch
as heat buildup would occur with subsequent undesirable
dehydrohalogenation of the resin. Since CPVC resins generally require
processing at high temperatures, such dead or lull spots would act as a
catalyst and generally impair the entire resin subsequently produced if
such spots were not eliminated. If the molecular weight of the CPVC was
reduced, the CPVC resin would have low cohesiveness and a tendency to
adhere to metal parts such as the extruding or die equipment. Lower
molecular weight moreover resulted in a more fluid resin which often would
flow into undesired and undesigned portions of the extruding equipment.
Polyvinyl chloride (PVC) resins when cross-linked have been found to have
increased torque with regard to processing the same. Hence, it was
unexpected that crosslinked chlorinated polyvinyl chloride (CPVC) resins
would have reduced processing torque.
SUMMARY OF THE INVENTION
It is therefore an aspect of the present invention to provide a composition
of a crosslinked chlorinated polyvinyl chloride resin which has good melt
strength and yet improved processing properties such as reduced melt
temperatures and reduced torque processing requirements. The crosslinked
CPVC resin is desirably produced by crosslinking PVC and subsequently
chlorinating the same such that from about 58 percent to about 70 percent
by weight of the crosslinked copolymer is chlorine. The polyvinyl chloride
resin can generally be polymerized according to conventional processing
techniques such as suspension, emulsion, or mass polymerization. The
amount of crosslinking agent is an effective amount to yield a suitable
processing torque reduction such as at least a 5 or 10 percent reduction
in working torque, and the like. Often various amounts of non-crosslinked
CPVC and/or non-crosslinked PVC can be utilized which do not adversely
affect the processing properties of the crosslinked CPVC resin.
DETAILED DESCRIPTION OF THE INVENTION
According to the present invention, compositions containing crosslinked
chlorinated polyvinyl chloride polymers and copolymers thereof are
prepared according to any conventional process. Although polyvinyl
chloride homopolymers are preferred, copolymers thereof can also be
utilized. The copolymer is made by polymerizing vinyl chloride monomer
with a vinyl component monomer. By the term "vinyl component," it is meant
a vinyl type monomer other than vinyl chloride. Such monomers are well
known to the art and to the literature and include esters of acrylic acid
wherein the ester portion has from 1 to 12 carbon atoms, for example,
methyl acrylate, ethyl acrylate, butyl acrylate, octyl acrylate,
cyanoethyl acrylate, and the like; vinyl acetate; esters of methacrylic
acid wherein the ester portion has from 1 to 12 carbon atoms, such as
methyl methacrylate, ethyl methacrylate, butyl methacrylate, and the like;
styrene and styrene derivatives having a total of from 8 to 15 carbon
atoms such as alpha-methylstyrene, vinyl toluene, chlorostyrene; vinyl
naphthalene; diolefins having a total of from 4 to 8 carbon atoms such as
butadiene, isoprene, including halogenated diolefins such as chloroprene;
monoolefins having from 2 to 10 carbon atoms and preferably 2 to 4 carbon
atoms; and the like; and mixtures of any of the above types of monomers
and other vinyl monomers copolymerizable therewith known to the art and to
the literature. An amount of vinyl chloride monomer is utilized to produce
a copolymer containing from about 70 to about 95 percent by weight, and
preferably from about 80 to about 93 percent by weight of vinyl chloride
repeating units therein. The remainder of the copolymer is made up of the
one or more above-noted vinyl component monomers, for example, vinyl
acetate. Thus, an amount of vinyl component monomer when utilized to
produce a copolymer is from about 5 to about 30 percent and preferably
from about 7 to about 20 percent by weight of vinyl component repeating
units therein.
The crosslinked polyvinyl chloride polymers or copolymers of the present
invention can generally be made according to any process route such as
suspension polymerization, bulk polymerization, emulsion polymerization,
mass polymerization, and the like, with mass polymerization generally
being preferred. Such polymerization methods are well known to the art as
well as to the literature.
It is an important aspect of the present invention that the chlorinated
polyvinyl chloride resin be crosslinked. Desirably, the vinyl chloride
copolymer and the preferred vinyl chloride homopolymer are initially
crosslinked before any chlorination thereof. That is, before any
chlorinated process step, polyvinyl chloride or copolymers thereof are
crosslinked. It is to be understood that a less preferred route is to
chlorinate such polymers or copolymers and subsequently crosslink the
same. Regardless of the particular process, the polymers or copolymers,
whether or not chlorinated can be crosslinked in any conventional manner
including those known to the art and to the literature. Generally, a
difunctional crosslinking agent is utilized. The cross-linking agents
which are suitable to produce the cross-linked PVC used in this invention
and contain two or more terminal polymerizable CH.sub.2 .dbd.C< groups per
molecule. Examples of this class of materials include
polyunsaturated--hydrocarbons, --polyethers, --polyesters, --nitriles,
--acids, --acid anhydrides, --ketones, --alcohols and polyunsaturated
compounds of this class incorporating one or more of these and other
functional groups. Specifically, there may be utilized divinyl benzene,
divinyl naphthalene, low-molecular weight and soluble polymerized dienes,
such as polybutadiene and other soluble homopolymers of open chain
aliphatic conjugated dienes, which soluble polymers do not contain any
appreciable number of conjugated double bonds, and other polyunsaturated
hydrocarbons; polyunsaturated esters such as ethylene glycol diacrylate,
ethylene glycol dimethacrylate, allyl acrylate, triacrylyl triazine,
hexallyl trimethylene trisulfone, and many others; polyunsaturated ethers,
such as divinyl ether, diallyl ether, dimethyl allyl ether, diallyl
ethylene glycol ether, diallyl, triallyl and other polyallyl ethers of
glycerol, butene-1,2-diol, 1-phenyl-1,2,3-propanetriol, the polyallyl,
-vinyl and -crotyl polyethers containing from two to seven or more of
these or other alkenyl ether groupings per molecule and made from
polyhydric alcohols such as the carbohydrate sugars, and the so-called
"sugar alcohols," including erythritol, pentaerythritol, arabitol, iditol,
mannitol, sorbitol, inositol, raffinose, glucose, sucrose, and many
others, and other polyhydroxy carbohydrate derivatives, the corresponding
polyalkenyl silanes, such as the vinyl and allyl silanes, and others. Of
this large class of crosslinking agents, the polyalkenyl polyethers of the
carbohydrate sugars, sugar alcohols and other polyhydroxy carbohydrate
type derivatives containing from two to seven alkenyl ether groups per
molecule are particularly useful. Such materials are easily prepared by a
Williamson-type synthesis involving the reaction of an alkenyl halide,
such as allyl chloride, allyl bromide, methallyl chloride, crotyl
chloride, and other like, with a strongly alkaline solution of one or more
of the polyhydroxy carbohydrate derivatives. Diallyl phthalate and divinyl
benzene are preferred.
The crosslinking agent can be added to the polymerization medium in any
manner known to those skilled in the art; such as premixing with the vinyl
monomer before charging, charging directly into the polymerization medium
or metering into the reaction during the polymerization. The preferred
method is to first premix the crosslinking agent with the vinyl monomer
before charging to the reaction vessel. If a mass polymerization is used
to produce the crosslinked PVC polymer, then the crosslinking agent can be
added at any location in the process such as the prepolymerizer or the
autoclave and preferably in the prepolymerizer.
The amount of crosslinking agent utilized is an effective amount to impart
unexpectedly improved processing properties when the crosslinked polymer
or copolymer is subsequently chlorinated, or to blends thereof, especially
reduced melt temperatures and reduced processing torque. By the term
"processing torque," it is meant the torque required for a specific
operation, that is, the torque required to perform a particular extruding
operation, injection molding operation, profile extrusion, and the like.
An effective amount of a crosslinking agent is such which generally
reduces the processing or working torque required for a particular
operation generally by at least 5 percent as from about 5 percent to about
20 percent and preferably by at least 10 percent as from about 10 percent
to about 15 percent. Naturally, the amount of torque reduction will
generally vary with the particular type of processing equipment utilized.
The amount of such crosslinking agents will vary depending upon the type
of crosslinking agents and the like. Generally, to obtain the above-noted
reductions in processing torque, the amount of crosslinking agent is
generally from about 0.025 to about 5.0 parts by weight, desirably from
about 0.1 to about 2.0 parts by weight, and preferably from about 0.1 to
about 0.5 parts by weight for every 100 parts by weight of the vinyl
chloride monomer or the vinyl chloride monomer and comonomer, which is to
be chlorinated or has previously been chlorinated. It is to be understood
that when blends are utilized, the non-crosslinked chlorinated polyvinyl
chloride and the non-crosslinked polyvinyl chloride are added to the
crosslinked chlorinated polyvinyl chloride after the crosslinked
chlorinated polyvinyl chloride has been made.
The polyvinyl chloride homopolymer or copolymer of the present invention
can be chlorinated in any conventional manner as well as according to any
manner known to the art and to the literature so that it contains high
amounts of chlorine therein, as for example from about 57 or 58 percent by
weight to about 70 percent by weight and preferably from about 65 percent
by weight to about 69 percent by weight based upon the total weight of the
polyvinyl chloride homopolymer or copolymer. One convenient method of
chlorinating either the crosslinked or the non-crosslinked vinyl chloride
polymers or copolymers of the present invention is to place the polymers
or copolymers in a water slurry containing chlorine therein and activating
the same as with ultraviolet light so that the chlorine is added to the
polymer chain.
Another aspect of the present invention relates to the utilization of
blends of the crosslinked CPVC resin of the present invention with
non-crosslinked CPVC resins in amounts which do not adversely affect the
processing properties, for example the processing torque reduction, of the
present invention. Generally, from about 0 percent to about 85 percent by
weight, desirably from about 0 percent to about 50 percent, and preferably
from about 0 percent to about 25 percent by weight of non-crosslinked CPVC
resins can be utilized based upon the total weight of the non-crosslinked
and the crosslinked CPVC resins. Additionally, non-crosslinked PVC resin
can be blended with the crosslinked CPVC resins of the present invention.
The amount of non-crosslinked PVC resin is from about 0 to about 40 parts
by weight, and preferably from about 0 to about 25 parts by weight per 100
parts by weight of said crosslinked CPVC resin or said blend of said
crosslinked CPVC resin and said non-crosslinked CPVC resin.
The crosslinked CPVC resins or blends thereof of the present invention can
contain common amounts of additives known to the art and to the
literature. Such conventional amounts are generally small, that is often
less than 10 parts by weight and preferably less than 5 parts by weight of
any particular additive based upon 100 parts by weight of the crosslinked
CPVC resin or blends thereof. Examples of the various conventional
additives which can be utilized include stabilizers, for example the
various tin stabilizers such as a tin thioglycolate, various impact
modifiers such as chlorinated polyethylene, acrylic based impact
modifiers, and the like, various lubricants such as oxidized polyethylene
wax, various pigments such as titanium dioxide, and the like. Such
additives are well known to the CPVC art.
As noted above, the use of crosslinked CPVC polymers or blends thereof
result in unexpected improvements in processing properties. That is,
crosslinked CPVC has improved melt strength (cohesive strength).
Heretofore problems such as dead spots, heat buildup areas and sticking to
hot metal and degradation, that is dehydrochlorination, are abated or
completely eliminated. The resulting increase in cohesive strength allows
for use of a lower apparent intrinsic viscosity resin which fuses easier
and flows at a lower melt temperature. In other words, the same melt
strength as non-crosslinked chlorinated polyvinyl chloride resins can be
obtained by utilizing the resins of the present invention with the
additional advantages that such resins of the present invention have lower
melt temperatures, or reduced processing torque, or both.
The crosslinked CPVC resins of the present invention, or blends thereof,
can be utilized wherever conventional CPVC resins have heretofore been
utilized as in profile extrusion. Areas of specific utility include pipes,
skylights, window glazing beads, and the like.
The invention will be better understood by reference to the following
examples.
EXAMPLES
Formula 1 relates to a control, that is a non-crosslinked CPVC composition
whereas formulas 2 and 3 relate to the crosslinked CPVC compositions of
the present invention.
______________________________________
CROSSLINKED CPVC EVALUATION
1 2 3
______________________________________
RECIPE, PHR
CPVC 100 -- --
1.1 IV, 68.5 percent chlorine)
Crosslinked CPVC (0.9
-- 100 --
Apparent IV
68 percent chlorine)
Crosslinked CPVC (0.74
-- -- 100
Apparent IV
68 percent chlorine)
Dibutyl Tin Bis Isooctyl
2 2 2
Thioglycolate -- -- --
Tyrin 3611, a chlorinated
4 4 4
polyethylene, manufactured
by Dow Chemical Co.
Paraloid KM-330, an acrylic
4 4 4
impact modifier, manufactured
by Rohm & Haas
AC 629A an oxidized poly-
1.125 1.125 1.125
ethylene manufactured by
Allied Signal
Titanium Dioxide (pigment)
5 5 5
RESULTS
DTS (410.degree. F.)
Time, Minutes 12.8 14.9 19.3
Torque, Meter-Grams
2710 2100 2100
Temperature, .degree.F.
224 223 225
Izod, ft-lbs/in 1.33 0.49 0.58
(1/8 inch, notched)
Vicat, .degree.C.
131 132 132
(Method B)
HDT, .degree.F. 217 212 217
(1/8 inch, 264 psi)
VHIT, in-lbs/mil 1.17 0.72 --
(1/4 inch tup)
Tensile, psi 7977 8140 --
Tensile Modulus, psi
336,000 335,333 --
% Elongation 70% 23% --
______________________________________
As apparent from the above data, most of the physical properties obtained
by compounds 2 and 3 of the present invention were similar to the control,
although some loss in impact strength was noted. However, a dramatic
torque reduction, in excess of 20 percent, was obtained. As previously
noted, it was unexpected that crosslinked CPVC compounds would result in
such a torque reduction.
Table II sets forth a comparison of conventional CPVC resins to crosslinked
CPVC resins of the present invention. Table III relates to blends of
crosslinked CPVC with non-crosslinked CPVC resins.
TABLE II
__________________________________________________________________________
COMPARISON OF CONVENTIONAL CPVC RESIN TO CROSSLINKED CPVC
1 2 3 4 5
__________________________________________________________________________
Base Resins
PVC Type Mass
Mass
Mass
Suspension
Mass
Crosslinked
Inherent Viscosity
0.68
0.76
0.84
0.92 Apparent 0.74
CPVC, % Cl.sub.2
67 68 68 67 68
Evaluation Recipe PHR
CPVC Resin 100
MBS Impact Modifier
9
Chlorinated Polyethylene
3
Dibutyltin Bis-Isooctyl Thioglycolate
2
Oxidized Polyethylene
1.5
Fatty Acid Ester Wax
0.5
Titanium Dioxide 1
Test Results
Dynamic thermal Stability
Maximum Temperature, .degree.F.
433 443 448 441 438
Stability Time, Minutes
14.7
14.5
9.3
4.4
9.7
Minimum Torque, Meter-Grams
1900
2420
2720
3180 2190
Notched Izod, Foot-Pounds/Inch
5.5 5.0 7.0 6.5 2.0
(1/8 Inch Specimen)
Instron Capillry
Rheometer
Apparent Viscosity at 745 sec .sup.-1, Poise
190.degree. C. 16,000
22,500
23,600
18,100
18,400
210.degree. C. 9,500
13,400
12,550
12,100
12,350
230.degree. C. 7,300
9,200
9,200
9,000
8,650
Brabender Extrusion
4
3
3
2 3
Life Test, Rating
(1 = Best, 5 = Worst)
__________________________________________________________________________
TABLE III
______________________________________
BLENDS OF CROSSLINKED CPVC WITH
NON-CROSSLINKED CPVC
1 2 3 4 5
______________________________________
Evaluation Recipes
68% Cl.sub.2 CPVC Resin
75 75 75 60 85
63.5% Cl.sub.2 CPVC Resin
25 -- -- -- --
68% Cl.sub.2 Crosslinked
-- 25 25 40 15
CPVC Resin
MBS Impact Modifier
8.5 8.5 10 10 10
Dibutyltin Bisisoctyl
2.5 2.5 2.5
2.5 2.5
Thioglycolate
Acrylic Processing Aids
3 3 3 3 3
Oxidized Polyethylene
1.5 1.5 1.5
1.5 1.5
Fatty Acid Ester Wax
1 1 1 1 1
Titanium Dioxide
5 5 5 5 5
Test Results
Notched Izod, Ft-Lbs/In.
7.9 2.0 2.7
2.4 5.8
(1/8 Inch Specimen)
Variable Height
1.76D 1.56SB 0.9B 1.1SB 0.9B
Brabender Extrusion
3 4 3 4 3
Life Test, Rating
(1 = Best, 5 = Worst)
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D = Ductile
SB = SemiBrittle
B = Brittle
As apparent from Table II, the crosslinked CPVC resin resulted a dramatic
reduction in the torque viscosity.
As apparent from Table III, the utilization of minor amounts of
non-crosslinked CPVC resin with crosslinked CPVC resin did not hurt
processability of the blend as noted by the Brabender Extrusion Life Test.
While in accordance with the Patent Statues, the best mode and preferred
embodiment have been set forth, the scope of the invention is not limited
thereto, but rather by the scope of the attached claims.
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